Intraoperative versus postoperative suture adjustment after penetrating keratoplasty

Post-penetrating keratoplasty astigmatism

Postoperative astigmatism is one of the common complications affecting visual outcomes after a penetrating keratoplasty. It can result from various factors related to host, donor and surgical technique, resulting in suboptimal visual outcome. While some of the measures taken during preoperative planning and during actual surgery can reduce the magnitude of postoperative astigmatism, postoperative correction of astigmatism is often required in cases with high degrees of astigmatism. When spectacles and contact lenses fail to provide optimal visual outcomes, various surgical techniques that include astigmatic keratotomy, compression sutures, toric intraocular lens placement, and laser refractive procedures can be considered. When none of these techniques are able to achieve a desired result with in the acceptable optical range, a repeat keratoplasty is considered a last option. We discuss the various causes and management of complication of postoperative astigmatism occurring after a full thickness corneal transplantation surgery.

Automated digital analysis of intraoperative keratoscopy and its correlation with postoperative astigmatism after big-bubble deep anterior lamellar keratoplasty

PURPOSE

To investigate the correlation between postoperative corneal astigmatism (PCA) and values of intraoperative keratoscopy analyzed with a newly developed automated technique in patients undergoing big-bubble (BB) deep anterior lamellar keratoplasty (DALK).

METHODS

Photographs of keratoscope rings taken at the end of BB-DALK were analyzed using ImageJ for the calculation of "roundness" (R): values = 1 indicate a perfect circle. Pearson's correlation was used to evaluate the relationship between R and PCA that measured 1 week (V1), 3 months (V2), and 18 months (V3), postoperatively. The area under the curve (AUC) of receiver operating characteristic (ROC) curve was used to evaluate the accuracy of R for identifying patients with PCA < 3 diopters (D). The point on the ROC curve nearest to the coordinate (0,100) was used as a cutoff to determine sensitivity and specificity.

RESULTS

Data from 121 patients were included. The mean value of R*was 0.93 ± 0.04 (range 0.76-0.99). R showed a significant correlation with PA at V3 (R = - 0.42, P < 0.01). The ROC curve had an AUC of 0.69 (95% CI 0.59-0.79). A cutoff value of R = 0.93 had a sensitivity of 70.3% and specificity of 61.0% for identifying patients with PA < 3D at V3.

CONCLUSIONS

This new digital analysis of keratoscope rings allows to identify with reasonably good diagnostic accuracy patients with low values of post-DALK astigmatism correctable with spectacles.

Cataract surgery after deep anterior lamellar keratoplasty and penetrating keratoplasty in age- and disease-matched eyes

PURPOSE

To assess the efficacy and safety of cataract surgery after deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PKP).

SETTING

Tokyo Dental College Ichikawa General Hospital, Chiba, Japan.

DESIGN

Retrospective case series.

METHODS

Age-matched and disease-matched eyes that had phacoemulsification and intraocular lens insertion after DALK or PKP were studied. Graft clarity was assessed at the final follow-up. The difference in the endothelial cell density (ECD), corrected distance visual acuity (CDVA), spherical equivalence, and refractive error between the expected values and values 1, 3, 6, and 12 months after cataract surgery were compared between the 2 groups.

RESULTS

Indications for keratoplasty were corneal stromal scar (22 eyes), lattice dystrophy (2 eyes), keratoconus (2 eyes), and postherpetic keratitis (4 eyes). All 30 eyes in each group had successful cataract surgery after keratoplasty. Graft clarity rates were 90.0% and 80.0% in the DALK group and PKP group, respectively (P = .47). The decrease in ECD at 12 months was significantly greater in the PKP group than in the DALK group (8.7% [SD] ± 21.7% versus 26.3% ± 27.8%) (P = .043). The CDVA was significantly improved in both groups. At 1 month, the mean refractive error was -0.5 diopter (D) ± 2.4 (SD) in the DALK and -0.4 ± 1.9 D in the PKP groups and remained stable thereafter.

CONCLUSIONS

Cataract surgery was successfully performed in eyes that had DALK or PKP, providing excellent visual and refractive outcomes. In cases of combined cataract and corneal pathology, and in the absence of endothelial involvement, DALK followed by cataract surgery might cause less endothelial damage.

Penetrating Keratoplasty Performed by Residents Compared With an Experienced Cornea Transplant Surgeon

BACKGROUND

Reports on keratoplasty by residents are rare compared to those on cataract surgery. The aim of this study was to compare the results and surgery time of penetrating keratoplasty performed by residents and an experienced cornea surgeon.

METHODS

The medical records and surgery videos of the first 5 penetrating keratoplasty procedures by 4 residents were reviewed and compared with those in 20 penetrating keratoplasty procedures by an experienced cornea surgeon. Patients underwent penetrating keratoplasty at the Department of Ophthalmology, Tokyo Dental College, Chiba, Japan. The main outcome measures are graft survival, best-corrected visual acuity, postoperative astigmatism, decreased rate of graft endothelial cell density, and details of surgery time.

RESULTS

Graft survival, best-corrected visual acuity, and postoperative astigmatism were not significantly different between residents group and the experienced surgeon group. The average decrease of graft endothelial cell density owing to surgery in residents and the experienced surgeon were 19.0 ± 17.5 and 18.5 ± 12.1%, respectively (p = 0.27, Mann-Whitney U test). The average surgery time taken by residents was 66.9 ± 18.1 minutes, and that by the experienced surgeon it was 28.2 ± 7.9 minutes (p = 0.0071, Mann-Whitney U test). Residents required the most time for running suture technique.

CONCLUSIONS

The results of keratoplasty by residents were similar with those done by the experienced surgeon. Surgery time was the only statistically significant difference (p = 0.0071), which did not influence surgical results.

How Much Progress Has Been Made in Corneal Transplantation?

To assess the benefits of component lamellar corneal surgery, we investigated the surgical outcomes of deep anterior lamellar keratoplasty (DALK) for keratoconus and Descemet stripping automated endothelial keratoplasty (DSAEK) for laser iridotomy-induced bullous keratopathy (LI-BK). The results were compared with the surgical outcomes of penetrating keratoplasty (PKP). Seventy-nine eyes with keratoconus treated with DALK and 81 eyes with LI-BK treated with DSAEK were studied, and the graft clarity rate, best spectacle-corrected visual acuity, endothelial cell density (ECD), and surgical complications were compared with 273 eyes with keratoconus and 98 eyes with LI-BK all treated with PKP. Keratoconus eyes showed excellent visual outcomes with DALK and PKP, but graft survival was higher for PKP (100%, 98.9%, and 96.3% vs. 98.6%, 90.6%, and 86.1%, at 1, 3, and 5 years after surgery, respectively; P < 0.0001). There were no significant differences in the ECD up to 1 year after surgery. Greater ECD decline was observed for PKP at 3 and 5 years after surgery. Descemet membrane microperforation was observed in 49 eyes treated with DALK. Postoperative complications in eyes treated with PKP were increased incidence of immunological rejection and secondary glaucoma compared with eyes treated with DALK. LI-BK graft survival rates were excellent in both groups (DSAEK: 89.6% and 86.1%; PKP: 100% and 98.6%, 1- and 2-year rates, respectively; P = 0.17). Best spectacle-corrected visual acuity was better in the DSAEK group, and ECD showed a higher rate of decrease with DSAEK than with PKP. DALK and DSAEK considerably improved surgical outcomes in eyes with keratoconus and those with LI-BK, respectively. However, several key areas require further work, including development of safe surgical methods in DALK and prevention of early postoperative ECD loss in DSAEK.

Does the type of suturing technique used affect astigmatism after deep anterior lamellar keratoplasty in keratoconus patients?

PURPOSE

To compare the effect of three different suturing techniques on astigmatism after deep anterior lamellar keratoplasty (DALK) in patients with keratoconus.

METHODS

In this retrospective study, 54 eyes of 54 patients with advanced keratoconus underwent DALK with three suturing techniques: single running, interrupted running, and combined interrupted and running. Postkeratoplasty astigmatism was evaluated during examinations 1, 3, and 6 months postoperatively and 2 months after completing suture removal.

RESULTS

Twenty-four eyes had single running sutures, 16 eyes had interrupted sutures, and in 14 eyes the suturing technique used was combined interrupted and running sutures. Mean age was 25.6 ± 5.9 years, 27.3 ± 6.8 years, and 26.5 ± 5.7 years (P = 0.422), and postoperative astigmatism 1 month after surgery was 3.79 ± 1.19 D, 5.56 ± 1.78 D, and 4.21 ± 1.55 D in the three groups, respectively (P = 0.012). However, 2 months after completing the suture removal, final postoperative astigmatism was 3.43 ± 1.44 D, 3.87 ± 1.38 D, and 3.71 ± 1.46 D (P = 0.846). Final astigmatism less than 4 D was seen in 18 cases (75%) in the single running group, nine cases (56.2%) in the interrupted running group, and nine cases (64.2%) in the combined interrupted and running group (P = 0.08).

CONCLUSION

Postkeratoplasty astigmatism is comparable with three different suturing techniques used in patients with keratoconus after completing suture removal in DALK. Due to earlier suture removal in DALK, the type of suturing technique used is not considerably important.

Comparison of the effect of three suturing techniques on postkeratoplasty astigmatism in keratoconus

PURPOSE

To compare the effect of 3 common suturing techniques on postkeratoplasty astigmatism and final best corrected visual acuity (BCVA) in patients with keratoconus.

METHODS

In this randomized clinical trial, 103 eyes of 103 patients with advanced keratoconus, who were contact lens intolerant, or with contact lens-corrected visual acuity less than 20/80, underwent penetrating keratoplasty with 3 suturing techniques: interrupted (IR), single running (SR), and combined interrupted and running (CIR). Postkeratoplasty astigmatism and BCVA were evaluated during regular examinations 1.5, 3, 6, and 12 months postoperatively and 2 months after complete suture removal. Suture adjustment and selective suture removal were performed 2 to 6 weeks and after 3 months in eyes with more than 4 D of corneal astigmatism in the SR and IR/CIR groups, respectively.

RESULTS

Of 87 patients who completed follow-up, 26 eyes underwent PK with interrupted suturing technique (IR), 26 eyes had single running sutures (SR), and in 35 eyes, the suturing technique was combined (interrupted + running sutures; CIR). Mean age was 27.2 +/- 8.4, 28.9 +/- 8.7, and 30.3 +/- 8.7 years, and postoperative astigmatism 1.5 months after surgery was 3.77 +/- 1.68, 5.48 +/- 2.09, and 4.10 +/- 1.79 D in the 3 groups, respectively (P = 0.015). However, 2 months after complete suture removal, final postoperative astigmatism was 3.83 +/- 1.65, 3.37 +/- 1.9, and 3.88 +/- 2.79 D (P = 0.851) and BCVA (log MAR) was 0.08 +/- 0.14, 0.13 +/- 0.23, and 0.09 +/- 0.16, respectively (P = 0.53). Immunologic endothelial rejection reactions were seen in 5 eyes (19.2%) in the IR group, 3 eyes (11.72%) in the SR group, and 6 eyes (17.64%) in the CIR group (P = 0.44). There was no case of graft failure during the follow-up period.

CONCLUSION

Postkeratoplasty astigmatism and BCVA are comparable with the 3 common suturing techniques (IR, SR, and CIR) in patients with keratoconus, provided that regular postoperative examinations and topography-guided suture adjustment and/or removal are performed.

Deep lamellar keratoplasty by intracorneal dissection: a prospective clinical and confocal microscopic study

OBJECTIVE

To evaluate the clinical findings, visual outcomes, and confocal microscopic corneal features of a surgical technique for manual deep lamellar keratoplasty (DLKP) with intentional sparing of the most posterior stroma.

DESIGN

Noncomparative, prospective, 12-month interventional study.

PARTICIPANTS

Forty-six eyes of 45 patients who had corneal pathologic features without endothelial abnormalities and requiring corneal graft were treated by DLKP by manual stromal delamination. They were examined clinically after surgery and using in vivo confocal microscopy at 2 weeks and 1, 3, 6, and 12 months.

INTERVENTION

The surgical technique consisted of an intracorneal deep manual stromal dissection through a 4-mm limbal incision at 50 mum from Descemet's membrane (DM). After trephination, an endothelial free graft was sutured.

MAIN OUTCOME MEASURES

Topographic parameters, interface depth and reflectivity, and anterior and postinterface keratocyte density; visual acuity was correlated with these parameters.

RESULTS

Two eyes had rupture of the DM. Two eyes that had delayed epithelial healing because of graft override with stromal inflammation underwent a second surgery (penetrating keratoplasty). Mean uncorrected logarithm of the minimum angle of resolution (logMAR) uncorrected visual acuity and logMAR best-corrected visual acuity (BCVA) improved from preoperative values (1.342+/-0.239 and 0.923+/-0.226, respectively) to 0.421+/-0.122 and 0.104+/-0.068, respectively, at 12 months. Mean topographic astigmatism was 3.09+/-1.30 diopters (D) at 3 months after suture adjustment, and 2.87+/-0.92 D at 12 months after suture removal. Average interface depth was 64.2+/-6.7 microm at 15 days and showed no significant changes up to 12 months. Mean interface reflectivity was highest at 15 days (95.5+/-15.7 light reflectance units [LRU]) and showed a progressive decrease over time of 55.3+/-8.7 LRU at 12 months. A significant negative correlation was observed between BCVA and topographic astigmatism up to 1 month and between BCVA and interface reflectivity starting from 6 months after surgery.

CONCLUSIONS

Deep lamellar keratoplasty by intracorneal dissection provides visual and clinical results comparable with that of other DLKP techniques. Visual recovery is slow and progressive, taking up to 1 year. Confocal microscopy enables precise evaluation of corneal features, interface morphologic features, and reflectivity, demonstrating a negative correlation between interface reflectivity and BCVA showing that the progressive recovery over months of the interface transparency is correlated with the increase in visual acuity after 6 months.

Contact lenses and special back surface design after penetrating keratoplasty to improve contact lens fit and visual outcome

AIMS

To describe the fitting of patients with high or irregular astigmatism following penetrating keratoplasty with contact lenses and to answer the question whether or not contact lenses with special back surface design can improve visual acuity in complex cases after penetrating keratoplasty.

METHODS

28 eyes were included. They were fitted with contact lenses with a special back surface that was designed for optical rehabilitation after penetrating keratoplasty. Four different types of these lenses (tricurve, keratoconus, reverse, oblong) were used selectively depending on abnormal eccentricity determined by videokeratoscope. The patients were followed up for an average period of 15.5 months. Lens tolerance and corrected visual acuity were evaluated and compared with that corrected with spectacles.

RESULTS

The visual acuity was significantly improved in nearly all eyes with an average increase of 3.6 lines (maximal nine lines) accompanied by good contact lens tolerance and satisfactory contact lens fit. No noticeable complications were observed.

CONCLUSION

Contact lenses with special back surface design can improve visual results and lens tolerance, and minimise problems in contact lens fitting. This is in favour of contact lenses as an alternative to surgical procedures for correction of high or irregular astigmatism after penetrating keratoplasty. This procedure is recommended especially in cases of patients who decline further operative interventions.

Efficacy of core vitrectomy preceding triple corneal procedure

AIMS

To evaluate the effectiveness of core vitrectomy preceding triple corneal procedure (penetrating keratoplasty, extracapsular cataract extraction, and intraocular lens (IOL) implantation).

METHODS

Thirty one consecutive eyes of 31 patients with indication for triple corneal procedure were randomly assigned to either triple procedure with core vitrectomy (vitrectomy group) or without vitrectomy (control group). The success rate of IOL implantation, IOL positioning, intraoperative and postoperative complications, endothelial cell loss, and best corrected visual acuity (BCVA) were compared. Follow up period was six months. Factors that may contribute to vitreous pressure elevation were also investigated in each case.

RESULTS

There was no statistically significant difference in each clinical parameter examined except a tendency of facilitating IOL implantation (p = 0.11). There were two cases of vitreous loss in the control group. Retinal detachment was not seen in any of the cases. The body mass index and age were related to higher vitreous pressure (p<0.05).

CONCLUSION

Core vitrectomy preceding triple corneal procedure is not necessary for all cases.

Same-Size Donor Corneas for Myopic Keratoconus

OBJECTIVE

To determine the efficacy of using same-size donor grafts for keratoconus patients with axial myopia.

METHODS

A prospective noncomparative interventional case series was performed on 142 eyes of 136 consecutive keratoconus patients. Penetrating keratoplasty (PKP) was performed by 3 skilled surgeons using the same technique with a single running 10-0 nylon suture. Donor button size was determined by a study protocol, where a same-size donor was used for eyes with an axial length (AXL) longer than 24.50 mm, whereas a 0.25-mm-oversized donor was used for eyes shorter than 24.49 mm. Postoperative spherical equivalent (SE) and incidence of postoperative complications were analyzed.

RESULTS

Of the 142 consecutive eyes, 123 eyes were operated according to protocol. The average postoperative SE on last visit was -3.94 +/- 3.21 D, with an average uncorrected visual acuity of 0.28 (0.90 average corrected). Postoperative SE correlated inversely (r = 0.46) with preoperative axial length (AXL) expressed by the equation: SE = -0.15 (AXL)2+6.40 (AXL)-71.82. Graft rejection was observed in 7 eyes (5.7%), and glaucoma in 2 eyes that required surgery.

CONCLUSIONS

Using same-size donor grafts in keratoconus patients with a long visual axis is a safe and effective procedure in reducing postoperative myopia.

Keratometric astigmatism after suture removal in penetrating keratoplasty: double running versus single running suture techniques

BACKGROUND AND OBJECTIVE

To compare astigmatism after suture removal in a retrospective sequential series of patients who had penetrating keratoplasty with either a double running suture technique or an adjustable single running suture technique. During the first year postkeratoplasty, when sutures were in place, the latter technique had produced less astigmatism.

MATERIALS AND METHODS

Keratometry and keratometric astigmatism were measured before and after suture removal. We compared these variables in 30 grafts with the double running suture technique to the same variables in 24 grafts with the single running suture technique.

RESULTS

The final portion of the double running suture was removed 408 +/- 177 (mean +/- SD) days after keratoplasty, whereas the single running suture was removed 611 +/- 224 days after keratoplasty (P<0.001). After suture removal, there was no difference between the double running and single running groups in either mean keratometry [46.5 +/- 1.8 diopters (D) versus 45.6 +/- 2.0 D, P=0.09, minimum detectable difference (MDD)=1.5D] or mean astigmatism (4.6 +/- 2.7 D versus 5.2 +/- 3.2D, P=0.72, MDD=2.3).

CONCLUSION

In this consecutive series of corneal transplants performed by one surgeon, the results suggest no difference in astigmatism between the two suturing techniques after all sutures have been removed.

Surgical technique for control of postkeratoplasty myopia, astigmatism, and anisometropia

PURPOSE

We previously demonstrated that selective suture removal reduces keratoplasty astigmatism; however, a myopic shift was induced with the increasing number of interrupted sutures removed. This study is an attempt to determine the effects of a modified surgical technique on postkeratoplasty myopia, astigmatism, and anisometropia.

DESIGN

A cohort study compared with historical controls.

METHOD

Optical penetrating keratoplasties were performed on 92 eyes of 84 patients. The study group consisted of 92 consecutive penetrating keratoplasties performed using 12 interrupted 10-0 nylon sutures and a tight 12-bite continuous suture and an average K reading of 46.00 diopters for eyes undergoing combined and intraocular lens exchange procedures. All patients had refraction, keratometry, and videokeratoscopy postoperatively starting at 6 weeks and at the completion of selective suture removal.

RESULTS

Before suture removal, the average spherical equivalent was -0.160 +/- 3.59 diopters; it was -1.58 +/- 3.66 diopters at the completion of suture removal at 1 year and -1.44 +/- 3.72 at the last follow-up visit, averaging 20.7 months. Final refractive, keratometric, and videokeratoscopy astigmatism was 2.81 +/- 1.82, 4.19 +/- 2.94, and 3.58 +/- 2.03 diopters, respectively. Anisometropia, using the spherical equivalent of the operated and fellow eyes, was 2.49 +/- 2.25 diopters at completion of the study. A best-corrected visual acuity of 20/50 or better was achieved in 59% of patients.

CONCLUSIONS

Low myopic spherical equivalent and anisometropia were achieved using a K reading of 46 diopters for calculation of intraocular lens power. The use of tighter continuous sutures and selective removal of fewer interrupted sutures only served to increase final astigmatism, with no significant effect on the final spherical equivalent.

Corneal opacity and cataract: triple procedure versus secondary approach

PURPOSE

To determine the efficacy of planned secondary cataract surgery after keratoplasty.

METHODS

Twenty patients (22 eyes) with simultaneous corneal pathology and cataract were enrolled in a prospective, interventional, case-matched, nonrandomized comparative trial. Penetrating keratoplasty (PKP) and extracapsular cataract extraction (ECCE) with IOL insertion (triple procedure) were performed in 11 eyes, and planned phacoemulsification (PEA) with IOL insertion after PKP was performed in 11 case-matched eyes.

RESULTS

There were 10 eyes (91%) within +/-2.0 D of expected values in the secondary PEA group versus 5 patients (45%) in the triple procedure group. No difference was observed in endothelial cell density after 1-year follow-up.

CONCLUSIONS

Planning for secondary PEA in PKP patients with cataracts is a safe and reliable procedure to obtain less post surgical refractive error. Performing a two-stage intervention has no effect on corneal endothelial viability after 1 year.

Randomized clinical trial of deep lamellar keratoplasty vs penetrating keratoplasty

PURPOSE

To prospectively compare the safety and efficacy of deep lamellar keratoplasty (DLKP) and penetrating keratoplasty (PKP).

DESIGN

Prospective, randomized clinical trial.

METHODS

Consecutive 26 eyes of 24 patients who had stromal opacity without endothelial abnormalities were randomly assigned to either PKP or DLKP. Best-corrected visual acuity (BCVA), contrast visual acuity, glare test, intraocular pressure, corneal topography, endothelial density, and pachymetry were measured before and after surgery.

RESULTS

Two eyes in the DLKP had rupture of the Descemet membrane and one of the eyes developed endothelial decompensation. One eye in the PKP group showed decreases in vision due to secondary glaucoma. None of the eyes developed immunologic rejection. The PKP group showed a tendency of faster recovery in BCVA than the DLKP group, but the difference was not statistically significant. Contrast visual acuity, glare test, and corneal topography did not show significant differences between the two groups. The intraocular pressure was significantly higher at 12 months in the PKP group (P =.004), but not in the DLKP group (P =.41) compared with preoperative values. While the PKP group showed progressive decrease in endothelial density over 24 months, this was not observed in the DLKP group after surgery. Difference in endothelial density at 24 months reached statistical significance (P =.04).

CONCLUSIONS

We found that DLKP was superior to PKP in its safety such as continuous decreases of endothelium or increases in intraocular pressure. However, endothelial damage can also occur in DLKP, especially in cases of intraoperative Descemet membrane rupture. With the development of easier surgical techniques, DLKP may be a first choice of keratoplasty in most eyes without endothelial abnormalities.

Topographic analysis of corneal regularity after penetrating keratoplasty

PURPOSE

To evaluate the accuracy of the Holladay Diagnostic Summary of the EyeSys Corneal Analysis System in predicting the corneal visual acuity potential in patients who have undergone penetrating keratoplasty (PKP).

METHODS

Astigmatism patterns, refractive and topographic astigmatism, best spectacle-corrected visual acuity (BSCVA), and hard contact lens (HCL) visual acuity of 54 patients were analyzed 3 months after PKP and compared with the Potential Corneal Acuity (PCA) value predicted by the Holladay Diagnostic Summary.

RESULTS

Qualitative patterns of astigmatism (p = 0.01) and refractive (p = 0.002) and topographic (p = 0.0002) astigmatism were significantly correlated with PCA values. Using HCL visual acuities to correct the BSCVA (HCL-corrected BSCVA) for noncorneal causes of reduced vision, we found that the PCA values of 48.1% of the patients were within one line of the HCL-corrected BSCVA; 81.5% were within two lines; and 93.0% were within three lines.

CONCLUSION

The Holladay PCA measurement may be useful in the postoperative evaluation of the optical quality of the central corneal surface in patients who have undergone PKP.